In general, glass used in an automobile is classified according to its usage, for example, as a windshield, a rear widow, or a side window. When removed from an automobile, if not in a condition for recycling, such glass is often discarded in landfills, which results in environmental contamination because the glass is made of inorganic material. For this reason, various methods for recycling such glass have been developed.
The side window glass is advantageous over the rear window glass or the windshield glass in recycling thereof because generally the windshield glass comprises a thin film in order to prevent the glass from being shattered in the event of an accident and the rear window glass includes an electronic conductive wire for defrosting. Namely, for recycling the rear window glass and the windshield glass, it is necessary to conduct an additional process to remove the thin film and the conductive wire.
Japanese patent publication No. 2001-334248, for example, discloses a method for peeling off the thin film layer made of resin by applying a solution of potassium hydroxide, a solution of sodium hydroxide, a solution of sulfuric acid and peroxide of hydrogen. However, the method is disadvantageous in that complex procedures are required and toxic solutions such as sulfuric acid used must be treated with special caution after use. In the light of the cost and time involved in the additional processing, rear window glass and windshield glass fall into disuse without recycling.
Unlike a rear window glass or windshield glass, a side window glass typically does not include other elements such as an electric conductive wire or thin film, so that the recycling procedure thereof can be simplified in comparison with that of other glass.
For example, Korean patent publication No. 1999-34492 discloses an apparatus for collecting window glass from disused cars, which is comprised of a pneumatic cylinder, a link assembly, and a crusher for breaking the glass into pieces. Moreover, in Korean patent publication No. 2002-13028, another collecting apparatus including a turning device, a crush device having a punch element, and a protector, is disclosed.
However, most of the window glass of the disused cars are coated with a tinting film so as to block sun light. Such tinting film is mostly discolored due to exposure to sunlight so that it is not able to properly serve as a sun screen. In order to recycle such window glass, it is necessary to remove the tinting film attached on the window glass in advance. Namely, an adhesive applied between a window glass and a tinting film must be removed so as to peel off the tinting film from the window glass. In the prior art, the removing method for tinting film comprises steps of weakening the adhesive strength by applying alcohol or acetone on the surface of the tinting film, and peeling off the tinting film by means of a scraper.
However, such removing method according to the prior art includes many complex and labor intensive processes so that it becomes time consuming, resulting in an increase in the cost involved in recycling window glass. In addition, such removing method is disadvantageous in that an operator has to handle chemical compounds during the process.